Endocrinology - canine Flashcards
ACTH stim testing - when can a 1ug/kg dose be used for testing or monitoring hyperA?
Dogs receiving mitotaine or trilostane treatment
Aldridge JVIM 2016
ACTH stim testing - when should a 1ug/kg dose not be used for testing or monitoring hyperA? why?
Dogs being tested for diagnosis of hyperA using ACTH stim test.
23% difference in interpretation of results between 5ug/kg and 1ug/kg doses
Aldridge JVIM 2016
LDDST for hyperA diagnosis- what is the: Sens? Spec? PPV? NPV?
Sens 96.6
Spec 67.2
PPV 73.1
NPV 95.6
Bennaim JVIM 2017
What LDDST pattern has the highest PPV for HyperA diagnosis?
And the lowest?
Lack of suppression - 93.9
Partial suppression - 67.9
escape/inverse - 36.8
Bennaim JVIM 2017
Does perivascular administration of corticotropin impact the outcome of ACTH stim testing for monitoring treatment with trilostane of dogs with hyperA?
no
no significant difference in pre or post ACTH cortisol if given IV or perivascular
Johnson JVIM 2017
What is the index of individuality (IoI)?
What does a low IoI mean?
reflects the relationship between the within and between-individual variable for that parameter.
low IoI meands low within individual variability in comparison withits between individual variability.
Tests with low IoI are not well suited to pop-based reference intervals because the individual’s homeostatic set point covers only a small fraction of the populations reference interval. thus a test resul that is outside of the individuals homeostatic set point but within the pop reference interval would be falsely considered normal.
Gal JVIM 2017
What is the IoI of post ACTH stim cortisol in healthy dogs?
and the CD?
What does this mean?
IoI = 1.1 CD = 3.3 ug/dL (92 nmol/L)
This represents intermediate individuality.
False negatives can occur with Hypercortisolism when cortisol is outside of the individuals homeostatic set point but within the reference interval
CD should be >3.3 ug/dL (92nmol/L) to assure that the difference between sequential measurements is not due to biological or analytical variability.
Gal JVIM 2017
What is CD?
Critical difference betweeen sequential measurements of a test parameters is the difference not due to the components of biological or analysitcical variability. .
assists in telling whether the sequential test results are significantly different or if the difference is due to total variability in the test.
Gal JVIM 2017
Is there a difference in adrenal size between dogs with pituitary HyperA and dogs with atypical hyperA?
No
PDH - 6.4
Atypical 7.2
normal 5.3mm
Frank JVIM 2015
What is atypical hyperA?
Clinical signs of hyper cortisolaemia with not evidence of sex-hormone secreting adrenal tumour and hyperA screening test results wnl.
Suspected due to elevations in precursor hormones.
Frank JVIM 2015
What can increase 17-hydroxyprogesterone?
- atypical hyperA
- non adrenal neoplasia
- estrus, diestrus and pregnancy
Frank JVIM 2015
Is there a difference in hourly or sum cortisol concentrations between dogs with PDH and atypical HyperA?
hourly - different
PDH = 4.3, atypical = 2.9 control + 1.4
sum - no difference
Frank JVIM 2015
What is the MST for dogs post transsphenoidal hypophysectomy in dogs with PDH?
781 days
van rijn JVIM 2016
what is the 4 week post op survival for dogs post transsphenoidal hypophysectomy for PDH?
what % have remission confirmed?
91% alive
92% of these in remission
van rijn JVIM 2016
What % of dogs undergoing post transsphenoidal hypophysectomy for PDH management develop recurrence? What is the median time for this?
27%
median 555 days.
van rijn JVIM 2016
What differences do dogs that had recurrence of signs of hypercortisolaemia post transsphenoidal hypophysectomy from those without recurrence?
why are these important?
higher pituitary height/brain area ratio
higher pre-op basal urinary corticoid to creatinine ratio (UCCR)
Larger have less favourable outcomes.
survival time and disease free fractions negatively correlated with pituitary gland size as assess by pit height/brain area ratio.
van rijn JVIM 2016
what differences are there in dogs with PDH between those that have GB mucocoels and those that don’t?
- more severe clinical signs
- higher total cholesterol
- higer post ACTH stim cortisol at time of diagnosis
- <6kg more likely to have cholestatic disease
- req higher dose of trilostane for both GBM (2.5 x higher) and cholestasis (1.5 x higher)
likely associated with
- lipid soluable/hydrophobic characteristics of trilostane
- breed, genetic, female => cholesterol metabolism and bile secretion differences
Kim JVIM 2017
is there a significant benefit to checking pre-ACTH stim cortisol in dogs with PDH?
No
pre-ACTH cortisol failed to discriminate between PDH and non-adrenal illness.
Nivy JVIM 2018
Using what cut offs, is the sens and spec for ACTH stim in diagnosing PDH?
for diagnosis of PDH:
Cut off - 683 nmol/L (24.8ug/dL)
Sens 86%
spec 94%
Cut off - 718 nmol/L (26.0 ug/dL)
Sens 81%
Spec 100%
Nivy JVIM 2018
When are peak levels of melotonin?
when is SARDs more likely?
winter - shorter daylight hours.
Oh JVIM 2018
What is urine 6-sulfatoxymelatonin concentration and what dose it represent?
urine MT6 conc = accumulated amount of systemic melatonin over several hours and is less affected by fluctuations in circ concentrations
accounts for >70% of melatonin secreted.
conc in urine is 2-3 times greater than urine melatonin.
Oh JVIM 2018
Are there any hormonal differences betweeen dogs with PDH and SARDs?
Urine MT6 is higher in dogs with PDH (4.08) compared to dogs with SARDS (2.37)
no difference in melatonin, serotonin or dopamine
Oh JVIM 2018
Is there a difference in measurement of ACTH stim tests in well controlled hyperA at 3-6h post trilostane vs 9-12h post trilostane?
what is the clinical significance of this?
Yes - lower in the 3-6h compared to 9-12h
Dogs with low 3-6h and clinically well controlled may have normal 9-12h post trilostane ACTH stim suggesting that they are actually clinically well controlled and no dose adjustment is needed.
if concerned that has iatrogenic hypoA, can check 9-12h post trilostane to see if is elevated, supporting ongoing treatment.
Midence JVIM 2015
What is the MST in dog with untreated hyperA from diagnosis?
506 days.
Nagata JVIM 2017